Telephone system.



No. 824,856. 1 PATENTED JULY 3, 1906.

s. FOWLER.

TELEPHONE SYSTEM. APPLICATION FILED DEC-.10. 1903 W 25525: V r Iur ,7 EAmUELE-FuW1En a hand-generator.

tract the armature,

- UNITED STATES SAMUELB. FOWLER. OF LA ELELTRICXCOMPANY, OF INDIANA.

PATENT OFFICE.

TELEPHONE 'sYs'rEm.

Specification of Letters Patent.

" Patented July 3, 1906.

Application filed December 10, 1903. Serial no. 184,607.

To all whom it may concern:

' Be it known that I SAMUEL B. FOWLER a citizen of the United State of Indiana, have invented a certain newand useful Improvement in Telephone Systems, of which the following is a full, clear, concise, and exact -description, reference being had to the accomfipanying drawing,

forming a part-of this speci cation;

M lnvention relates to telephone systems, particularly to those known as local-battery systems, in which the talking-icircuit at the'subscribers substation is su p ed-from a local battery and from which su station call mg-current is'sent into the line usually from Herotofore in such systems the current from the substation-generator passed through the wind' s of an indicator-signal at the central exc ange to atassociated with a dro or locking mechanism.- Usually an armatureever was provided with a hook at its end to normally engage the top of the shutter, and upon the attraction of the armature the leverwas raised to allow them shutter to fall to display a signal. In some cases also a target or shutter was secured to the end of the armature-lever, which shutter was associated with locln'ng or detent mechanism which, upon raising of the target when the armature was attracted, served to prevent restoration of the. target until the operator either mechanicall' or electrically removed this lockin or de ent mechanism. As the shutter an looking or detent mechanism are in mechanical connection or contact with the armature parts, great current strength was necessary to attract the armature against the mechanical resistance offered-by the shutter or other mechanism, and OPGISIIOII of the al was not always certain. v nmyimproved system I employ arelay rovided with a winding normally bridged etween the limbs of the line and connected directly in circuit with the substatiomgenerator when actuated. This Windingi is preferably composed of many turns, an a very sli ht actuation of the substation-generator wi l sufficiently energize the relay-core to at tract an armature against a contact to close a local circuit through a source of'current and an ind'icating device, such as a lamp. This local circuit also includes a winding con- States, residing at La- Fayette, 1n the county of Tippecanoe and.

which was: mechanically sisting of a comparatively few number of turns also disposed about the relayc0re, and as the armature is attracted to close the local circuit upon actuation of the substation-generator this auxiliary coil then energizes the core to retain the armature in its closed position.- Both the local circuit and the circuit throu h the energizing-winding connected with t e substation-generator are connected with j ack-springs, and upon insertion of the plug into the jack the circuit throu h the energr -windmg is interru ted, an the local circuit is also opened to re ease the armature to extinguish the signal. The same principle may pa applied to provide for a clearing-out s1 a shall more clearly describe my'invention by reference to theaccompa'nying'drawing, in which I have illustrated two substations A and B to be connected for conversation through anoperators cord-circuit C. The subscriber A is shown as just havin notified central of a desired connection. ach substation is provided with' a hand-generator 1, which isnormally disconnected from the line, but upon actuation automatically connecting itself in circuit, as is well known in the art.

A switch-hook 2 when supporting the receiver ary 6 and the line-limbs, and a'local ta king circuit is-closed through the primarv 7, battery 8, transmitter 9, and the switch 00k 2. At the central exchange I' provide an indicating-relay'lO, provided with awinding .11, composed, preferably of a great'many turnsand connected Wit tact springs 12 12, which normally engage 1 the tip and sleeve sprin s 13 and 14 of the spring-j ack 15. An auxi iary coil 16 of comparatively few turns also surrounds the core of the relay 10 and is adapted for inclusion in a local circuit containing the relay-armature 17, the contact 18, signal-lamp 19, battery- GOIll of the receiver from the hook the receiver is included serially in circuit 'with, the second- 20, conductor 21, tip-spring 13, inner spring 12, and conductor-22.

Substation subscriberA now wishes to signal the central operator." The switch-hook will be down, as shown, at substation B, and upon actuation of the generator 1 a current will be sent over the'line-limbs through" the I will now glow and signal the central o,perator,

who inserts the answering-plug 23 in the spring-jack 1 5, thereupon disconnecting the springs 12 12 to disconnect the winding '11 from circuit and to open the local circuit to extinguish the indicating-lamp 19. The operator actuates the listening-key 24 to connect her telephone apparatus, 25 in circuit, and the subscriber A, having removed his receiver from the hook, after actuationof the generator], notifies central of the desired connection as, for instance, with the subscriber B. The operator may then insertthe calling-plug 26 into the spring-jack 27, connected with 'the'line leading to substation B, and upon actuation of ringing-key 2S send current from the generator 29 to actuate the signal-bell 5 at substation B; After subscriber at substation B has removed his re ceiver from the hook the two substations will be in telephonic communication. lay 30 may be similarly employed as the relay IO'to perform the functions of a clearingout relay, the winding 31 being in, this case bridged across the cord co'nductors32 and. 33 while the auxiliary winding 34 is included in a local circuit containing the armature 35,

contact 36, battery 37, and lamp 38.' When the subscribers have concluded their conversation, a slight actuationo't either substationgenerator will send current through the coil '31 to attract the armature 35 against the contact 36 to close the local circuit through the lamp 338, thus notifying'the operator that the conversation has terminated. To restore this localcircuitfl. imzlude tliicrein' a key 39, which may be placed in the most convenient position for the operator, and upon with drawalof the plugs from the' jacks a'lter termination of the ,:onversation a slight tap on the lroy 39-will open the local circuit to extinguish the-lamp 38, and the system is now again'norn'ial.

As the windings energized. from the sub- .station generators consist of 'a great many turns, very little current is necessary to cause a'ttraction 'of the relay-armature, and actuation of the indicating-signal will be assured through a Wide range ol" line resistance or disturbances. The auxiliary energizing coil, upon attraction of the armature, is included in localcircui t, the resistance of which is constant, and consequently activity oi the'lamp 19 will be Imiintaiiied.independent of line resistances and. conditions, thus assuring, a more elticient indicating-signal' or clearingout signal for local-battery systems Again,

A rehigh and that of the auxiliary winding comparatively low the local. circuit and the main circuit currents will not interfere or detract from each other.

I do not wish to be limited to the precise arrangementof apparatus and circuits as shown, as changes could easily be made without departing from the scope of the invention.

I claim as new and desire tosecure by Letters Patent I 1. In a. telephone-exchangesystem, the combination with a central exchange,

minating in a substation, acurrent-generator at said substation adapted-for connection with the telephone-line, afs'prin central exchange having" the inc-contacts of a,

telephone-lin extending therefrom and ter- 8 -.jack at the connected with .the limbso'f the. telephoneline, a relay atathe central exchange, a main,

winding for-saidrelay connected.With'auxil.-'

iary jack-springs normally in connection with the line jack-springs, I an additional Winding for said relay,- a local circuit'including sai winding and havin -its tenninals' connected said jac dine sprm'gsand one of said auxiliary springs normally 1n-conta'ct;-,

with one of the armature of said 'rela ,asource of current,

anda signal alsoinclude insaid 'localcircuit,

actuation of the substation enerator caus ing current-flow through saic main wmdin during the connectionof'said-generator wit 1 the line,.said armature upon'such-energiza- 7 tion of the relay serving to close. the local cirj cuit, whereby said source of current becomes active to maintain energization of said relay andclosure-of said local circuit, and a cor circuit at the] central exchange rovided with plugs, insertion of a plug into t espring ja'ck causing disengagement of the line-springs from the auxiliary s rings whereby both windings ofthe relay ecome inert and the local circuit openedf I 1;

2. In a telephone-exchange system, the combination with a central exchange, of-a telephonedine extending therefrom'and ter-,

minating in a'substatioh, an alternating cur-.

rent at the substation normall disconnected from the line but "adapted" or'connection' therewith-,a spring-jack at the centralexchange, line-springs for said spring-jack permanently connected with the limbs-of the telephone line,

springs, a relay'a't the central exchange, a main winding for said relay having lts terauxiliary springs for said spring-jack normally-connected with the line-' minals connected with the auxiliary contacts and normally connected therethrougli with.

the telephone-line limbs, an auxiliary Winding for said relay' having one terminal 0011-.

nected with the auxiliary spring, and its other terminal connected with the rela -.armature, alocal circuit at the centraexchange having its terminal connected with 1'30 as the rcsistancecol the ,inainwinding is very l the armature-contact andwith one of the linesprings, a source of current, and a signal in the relay-windin s to be entirely disconsaid localcircuit, actuation of the generator at nected from circuit, whereby said rela bethe substation causing current-flow through comes inert and the local circuit opene the line-limbs and through the main relay- Inlwitness whereof I hereunto subscribe 5 winding to cause energization thereof during my name this 7th day of December, A. D. r 5

actuation of the generator, whereby the relay- 190.3.

armature is attracted to close the local circuit SAMUEL B. FOWLER. to cause actuation of the signal, and a cord- Witnesses: circuit at the central exchange havingplugs, HENRY S. BULLOCK,

ro insertion of a plug in the spring-jack causing 'H. E1) DENIG. 

